The present invention relates to a method of improving the post-irradiation ductility of precipitation hardenable alloys and more particularly to those alloys which undergo a gamma prime hardening precipitation reaction. In general, it has been found that these alloys develop an optimum combination of strength and ductility when they are solution heat treated and precipitation hardened, such solution heat treating usually taking place at a temperature in excess of about 950.degree. C., following which the alloy is usually quenched to room temperature from such solution heat treatment temperature. It is a function of the solution heat treatment temperature to place into solid solution all of the components which will enter into the precipitation hardening mechanism. In this case, the iron-nickel-chromium matrix in its austenitic phase configuration is the solid solution into which such components as titanium and aluminum are taken into said solid solution. Following quenching to room temperature the alloys are heated usually to a temperature between about 600.degree. C. and about 825.degree. C. for discrete periods of time during which the titanium, aluminum and nickel are precipitated from the solid solution usually in the form of Ni.sub.3 (Ti, Al). This configuration is known as the gamma prime configuration and is effective for rendering the alloy with its optimum combination of strength and ductility.
In contrast thereto, the present invention has unexpectedly found that following solution heat treatment, which advantageously renders the alloy in its most workable condition, the alloy can be cold worked to effect a reduction in cross-sectional area of between about 10% and about 60% and, as cold worked, the alloy will exhibit sufficient strength and post-irradiation ductility as to make the composition of matter highly desirable for use in a nuclear reactor where the components are subject to high fluences during the operation of the reactor.